Radiation oncology journal最新文献

Purpose: For tonsillar cancer with multiple ipsilateral neck lymph nodes, the safety and efficacy of unilateral radiotherapy (RT) have long been a topic of debate. We performed retrospective analyses of patients having ipsilateral neck lymph nodes treated with unilateral RT in two tertiary referral hospitals.

Materials and methods: This study accrued 29 patients who were diagnosed as well-lateralized tonsillar cancer with multiple ipsilateral neck lymph nodes and underwent unilateral RT from March 2000 to March 2020. Patients underwent treatment with one of the following options or a combination of them: induction chemotherapy, surgery, RT, and concurrent chemoradiotherapy. We analyzed the recurrence pattern and survival with special attention to contralateral neck failure. Also, treatment-related toxicities were compared with a 1:1 matched cohort of those who received bilateral RT, using propensity score matching analysis.

Results: At a median follow-up of 68 months, no contralateral neck failure was observed. Five-year actuarial locoregional recurrence-free survival, distant metastasis-free survival, and overall survival were 85.6%, 91.8%, and 92.7%, respectively. Both the acute and chronic grade 2 xerostomia occurred in 10.3% of the patients. When the toxicity for unilateral RT was compared to that of bilateral RT using a propensity score-matched cohort, a significantly lower rate of acute xerostomia was observed in unilateral RT group (55.1% vs. 82.7%, p=0.002), primarily at grade 2 level (10.3% vs. 51.7%, respectively).

Conclusion: The results of our study suggest that unilateral RT can be safely performed in well-lateralized tonsillar cancer patients with multiple ipsilateral neck lymph nodes.

Purpose: To generate and investigate a supervised deep learning algorithm for creating synthetic computed tomography (sCT) images from kilovoltage cone-beam computed tomography (kV-CBCT) images for adaptive radiation therapy (ART) in head and neck cancer (HNC).

Materials and methods: This study generated the supervised U-Net deep learning model using 3,491 image pairs from planning computed tomography (pCT) and kV-CBCT datasets obtained from 40 HNC patients. The dataset was split into 80% for training and 20% for testing. The evaluation of the sCT images compared to pCT images focused on three aspects: Hounsfield units accuracy, assessed using mean absolute error (MAE) and root mean square error (RMSE); image quality, evaluated using the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) between sCT and pCT images; and dosimetric accuracy, encompassing 3D gamma passing rates for dose distribution and percentage dose difference.

Results: MAE, RMSE, PSNR, and SSIM showed improvements from their initial values of 53.15 ± 40.09, 153.99 ± 79.78, 47.91 ± 4.98 dB, and 0.97 ± 0.02 to 41.47 ± 30.59, 130.39 ± 78.06, 49.93 ± 6.00 dB, and 0.98 ± 0.02, respectively. Regarding dose evaluation, 3D gamma passing rates for dose distribution within sCT images under 2%/2 mm, 3%/2 mm, and 3%/3 mm criteria, yielded passing rates of 92.1% ± 3.8%, 93.8% ± 3.0%, and 96.9% ± 2.0%, respectively. The sCT images exhibited minor variations in the percentage dose distribution of the investigated target and structure volumes. However, it is worth noting that the sCT images exhibited anatomical variations when compared to the pCT images.

Conclusion: These findings highlight the potential of the supervised U-Net deep learningmodel in generating kV-CBCT-based sCT images for ART in patients with HNC.

Purpose: To evaluate recurrence patterns of and survival outcomes in glioblastoma treated with intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3D-CRT).

Materials and methods: We retrospectively examined 91 patients with glioblastoma treated with either IMRT (n = 60) or 3D-CRT (n = 31) between January 2013 and December 2019. Magnetic resonance imaging showing tumor recurrence and planning computed tomography scans were fused for analyzing recurrence patterns categorized as in-field, marginal, and out-of-field based on their relation to the initial radiation field.

Results: The median overall survival (OS) was 18.9 months, with no significant difference between the groups. The median progression-free survival (PFS) was 9.4 months, with no significant difference between the groups. Patients who underwent gross total resection (GTR) had higher OS and PFS than those who underwent less extensive surgery. Among 78 relapse cases, 67 were of in-field; 5, marginal; and 19, out-of-field recurrence. Among 3D-CRT-treated cases, 24 were of in-field; 1, marginal; and 9, out-of-field recurrence. Among IMRT-treated cases, 43 were of in-field; 4, marginal; and 10, out-of-field recurrence. In partial tumor removal or biopsy cases, out-of-field recurrence was less frequent in the IMRT (16.2%) than in the 3D-CRT (36.3%) group, with marginal significance (p = 0.079).

Conclusion: IMRT and 3D-CRT effectively managed glioblastoma with no significant differences in OS and PFS. The survival benefit with GTR underscored the importance of maximal surgical resection. The reduced rate of out-of-field recurrence in IMRT-treated patients with partial resection highlights its potential utility in cases with unfeasible complete tumor removal.

Adenoid cystic carcinoma is a malignancy that is difficult to treat and often metastasizes to the lung. Systemic chemotherapies are not effective for this tumor type, thus local therapies are frequently used. Here, we report a case demonstrating the use of extensive ablative interventions in controlling the progression of metastatic adenoid cystic carcinoma. A patient with adenoid cystic carcinoma developed numerous metastases to his lungs and liver. Local ablative therapies including interstitial brachytherapy and SBRT were used to treat approximately 80 different metastases over the course of a decade. Over 850 brachytherapy seeds were implanted in this patient, and the tumor control and patient outcome were good. As of the most recent follow-up in March 2024, the patient has survived for approximately 12 years since his diagnosis of adenoid cystic carcinoma. To our knowledge, this case represents the most brachytherapy treatments reported in a single patient. It highlights the utility of interstitial brachytherapy and SBRT in treating extensive lung and liver metastases.

Purpose: This study aimed to evaluate the impact of facilitating target delineation of continuous positive airway pressure (CPAP) in patients undergoing stereotactic ablative radiation therapy (SABR) for lung tumors by lung expansion and respiratory motion management.

Materials and methods: We performed a prospective single-institutional trial of patients who were diagnosed with either primary lung cancer or lung metastases and received SABR with a dose of 40 to 60 Gy in 4 fractions. Four-dimensional computed tomography simulations were conducted for each patient: once without CPAP and again with CPAP.

Results: Thirty-two patients with 39 tumors were analyzed, after the withdrawal of five patients due to discomfort. For 26 tumors separated from the diaphragm, CPAP significantly increased the superoinferior distance between the tumor and the diaphragm (5.96 cm vs. 8.06 cm; p < 0.001). For 13 tumors located adjacent to the diaphragm, CPAP decreased the overlap of planning target volume (PTV) with the diaphragm significantly (6.32 cm3 vs. 4.09 cm3; p = 0.002). PTV showed a significant reduction with CPAP (25.06 cm3 vs. 22.52 cm3, p = 0.017). In dosimetric analyses, CPAP expanded lung volume by 58.4% with a significant reduction in mean dose and V5 to V40. No more than grade 2 adverse events were reported.

Conclusion: This trial demonstrated significant improvement of CPAP in target delineation uncertainties for lung SABR, with dosimetric benefits, a favorable safety profile and tolerability. Further investigation is warranted to explore the role of CPAP as a novel strategy for respiratory motion management.

Purpose: This study aimed to evaluate the clinical outcomes and prognostic implications of regional nodal irradiation (RNI) after neoadjuvant chemotherapy (NAC) in patients with residual triple-negative breast cancer (TNBC).

Materials and methods: We analyzed 152 patients with residual TNBC who underwent breast-conserving surgery after NAC between December 2008 and December 2017. Most patients (n = 133; 87.5%) received taxane-based chemotherapy. Adjuvant radiotherapy (RT) was administered at a total dose of 45-65 Gy in 15-30 fractions to the whole breast, with some patients also receiving RT to regional nodes. Survival was calculated using the Kaplan-Meier method, and prognostic factors influencing survival were analyzed using the Cox proportional-hazards model.

Results: During a median follow-up of 66 months (range, 9 to 179 months), the 5-year disease-free survival (DFS) rate was 68.0%. The 5-year locoregional recurrence-free survival, distant metastasis-free survival, and overall survival rates were 83.6%, 72.6%, and 78.7%, respectively. In the univariate analysis, the cN stage, ypT stage, ypN stage, axillary operation type, and RT field were associated with DFS. Multivariate analysis revealed that higher ypT stage (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.00-3.82; p = 0.049) and ypN stage (HR = 4.7; 95% CI 1.57-14.24; p = 0.006) were associated with inferior DFS. Among clinically node-positive patients, those who received RT to the breast only had a 5-year DFS of 73.7%, whereas those who received RNI achieved a DFS of 59.6% (p = 0.164). There were no differences between the DFS and RNI.

Conclusion: In patients with residual TNBC, higher ypT and ypN stages were associated with poorer outcomes after NAC. RNI did not appear to improve DFS. More intensive treatments incorporating systemic therapy and RT should be considered for these patients.

Purpose: To evaluate the efficacy and toxicities of skin-directed radiotherapy (RT) in primary cutaneous T-cell lymphoma (CTCL).

Materials and methods: We retrospectively analyzed 57 CTCL lesions treated with skin-directed RT between January 2000 and December 2022. Lesions were categorized into three distinct groups: early-stage disease treated with local RT, advanced-stage disease treated with local RT, and advanced-stage disease treated with total skin electron beam therapy (TSEBT). Treatment outcomes, including response rates, recurrence patterns, and local progression probability, were assessed for each group.

Results: Mycosis fungoides (MF) constituted 90.9% of the advanced-stage pathologies, while CD4+ primary cutaneous small/medium T-cell lymphoproliferative disorder was common in the early stage lesions (55%). Median RT doses were 30.6 Gy, 27 Gy, and 32 Gy for the local RT with early stage, the local RT with advanced stage, and TSEBT with advanced stage, respectively. The complete response rates were high across the groups: 95.5%, 70.8%, and 90.9%, respectively. Seven local recurrences (29.2%) occurred in the local RT group with advanced stage, while seven patients (63.6%) in the TSEBT group experienced local failure. All recurrences were observed in lesions and patients with MF. Acute toxicities were mainly grade 1 or 2, with no grade 3 or higher events. No significant association between RT dose and local progression rates in MF lesions was found.

Conclusion: Skin-directed RT in CTCL is effective for local control and well-tolerated with less toxicity.